1. Field of the Invention
The present invention relates to the field of display technology, and in particular to a thin-film transistor (TFT) manufacturing method and a TFT manufactured with the method.
2. The Related Arts
The flexible display technology releases the designs of display devices from being constrained to be planar and allows for diverse outside configurations and designs, and demonstrating the characteristics of being thin and light-weighted and impact resistant, making it fit to applications for various portable devices, such as mobile phones, personal digital assistants (PDAs), and notebook computers. Display devices of this kind is flexible and deformable and is more resistant to damage, allows for mounting to a curved surface, and can be manufactured as electronic newspapers, television walls, and wearable displays, those being desired by general consumers, demonstrating incredible charming of organic semiconductors.
In addition, another important factor associated with the development of the flexible display devices is that the manufacturing operations can be changed from sheet-fed batch processing to roll-to-roll manufacturing. This means the manufacturing costs of the display devices can be significantly reduced. Due to having the same thickness and flexibility as those of paper sheets, possessing the same message updatability as that of digital electronic media, being advantageous in respect of mechanical properties, and exhibiting a cost advantage for manufacturing, it is quite likely that the flexible display devices may take the position of flat panel displays that are currently dominating the market and gain certain business opportunity in an emerging market.
A thin-film transistor liquid crystal display (TFT-LCD) is a liquid crystal display having liquid crystal pixels each of which is driven by TFTs integrated on a backside thereof, where a scanning process is adopted to arbitrarily control the ON/OFF state of each of the displaying spots so as to display messages in a manner of high speed, high brightness, and high contrast. An active matrix organic light emitting diode (AMOLED) display is, similarly, driven by using TFTs with each pixel is provided with a TFT having a function of switching, and each pixel provided with a charge storage capacitor, where an entire system of a peripheral driving circuit and a display array is integrated on the same substrate. A difference from the TFT structure of TFT-LCD is that LCD is driven by an electric voltage, while an AMOLED is driven by an electric current so that brightness thereof is proportional to the electric current so that in addition to an addressing TFT that performs a switching operation between ON/OFF states, a small driving TFT that has a reduced ON state resistance to allow for the passage of a sufficiently large electric current is also needed. A static random access memory (SRAM) is similarly driven by using a TFT.
In a conventional manufacturing process for the TFTs of the flexible display devices, the operation temperatures, particularly the operation temperature of plasma enhanced chemical vapor deposition (PECVD), are generally relatively high, imposing a severe requirement for temperature of a substrate. The substrate of a TFT of a flexible display device is generally made of organic polymer materials, which are not resistant to high temperatures so as to hinder the progress of the flexible display technology.